


Aging With Grace

by Two_of_Clubs



Category: Supernatural
Genre: Aging, Aging Dean Winchester, Alternate Universe - Canon Divergence, But mostly fluff, Domestic Fluff, Established Relationship, I don't know how else to describe it, Implied Sexual Content, Lots of domestic fluff, M/M, Men of Letters Bunker (Supernatural), Mild Hurt/Comfort, Non-Aging Castiel, Post-Season/Series Finale
Language: English
Status: Completed
Published: 2021-03-02
Updated: 2021-03-12
Packaged: 2021-03-14 16:49:01
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 8
Words: 8,716
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29794935
Author URL: https://archiveofourown.org/users/Two_of_Clubs/pseuds/Two_of_Clubs
Summary: The first thing Dean notices seems so little, so inconsequential that he nearly doesn't spot it in the first place. The second thing Dean notices, he discovers completely by accident. The third thing that catches Dean's attention happens in the last place he would have expected...Dean's not a young man anymore. He's in his forties now, and he can accept that. As for Cas? The angel still looks exactly the way he did when Dean first laid eyes on him all those years ago. And while Dean initially has a bit of a hard time coming to terms with that, Cas thinks he might have a solution.
Relationships: Castiel/Dean Winchester
Comments: 13
Kudos: 104





	1. Aches and Pains

**Author's Note:**

> So, this takes place sometime after the end of Season 15. There's no specific timeline here, I've basically just pretended the last few episodes never happened. No one dies, no one gets sent to super hell, it's just rainbows and butterflies, okay? (Well, mostly.) 
> 
> Also, in case the tags or summary weren't clear, this story is based on the idea that while Dean has aged the way a normal person would, Cas's vessel has physically remained the same since the two of them met. As you might guess, this presents a unique problem that they must now navigate.
> 
> Enjoy!

The first thing Dean notices seems so little, so inconsequential, that he nearly doesn’t spot it in the first place. It creeps up on him slowly, like it doesn’t want to be seen. Dean’s so busy working on the Impala, it almost escapes his attention altogether. _Almost._ He crouches down to check the tire pressure and inspect the rims, squatting like the catcher on a baseball team. But _that’s_ not when the problem presents itself. No, the problem comes when Dean goes to stand up, and his knees begin to protest. He grunts, more confused than he is in pain, and takes a couple of stiff steps over to the next tire. He repeats the same process, and gets the same result. _That’s different._

He ignores it, finishing his inspection of the tires and turning his attention to the Impala’s engine. He lifts the hood and checks the oil. _Looks good for now._ He’s in the middle of doing a quick scan when something catches his eye. It’s small, and Dean nearly doesn’t see it, tucked away along the edge of the engine well. As he leans closer, however, he can clearly see a thin, flathead screwdriver nestled in the space between the Impala’s engine and the shell of its body. Thankfully, it’s not in a spot where it could have caused any damage. Dean realizes it must have fallen out of his shirt pocket last week while he was replacing one of the spark plugs, and mentally kicks himself for being so careless around his pride and joy.

“I’m sorry, Baby,” he says, leaning over to collect the stray screwdriver. “It’s okay, let’s get rid of that.” 

Dean reaches down to get the tool, carefully sliding his hand into the small gap where the screwdriver has gotten stuck. He’s just _barely_ able to squeeze his hand into the narrow space, and even _that_ takes a little maneuvering. Finally, Dean gets a hold of it. He retrieves the screwdriver, standing up straight once more, when suddenly, the muscles in his back start to complain. _How? He was only bent over for a couple minutes._ He shakes his head, wiping the engine grease he got on himself while extracting the tool on his shirt. The wayward screwdriver goes back in his tool box, and the Impala’s hood comes down. The door to the garage opens, and Cas steps inside. He makes his way over to Dean, who’s still fully focused on his car. Dean knows there shouldn’t be any other stray objects hiding in there, but he wants to be sure. _He owes Baby that much._

“Hey, Dean,” Cas calls to him.

Dean peels his attention away from the Impala, his expression softening when he sees Cas.

“Hey, Cas,” he smiles.

The angel looks him up and down for a moment, then smiles to himself.

“What is it?” Dean asks.

“Somehow, you always manage to get dirty whenever you spend time out here.”

Cas points at the engine grease on Dean’s shirt. And hands. Dean shrugs. He then walks around to the front of the car and sits on the hood, looking at Cas intently.

“Don’t lie...” Dean grins. “You like it when I get dirty.”

The angel chuckles softly, biting his lip.

“Yeah...okay,” he admits.

Dean gestures for Cas to come closer. He does, and soon Dean is wrapping him in his arms, pulling Cas against him. Cas crowds in between Dean’s legs, his hands cupping Dean’s face as he leans down for a kiss. It’s sweet and gentle, leaving Dean with a smile on his face when they break apart.

“So what are you here for? A tire rotation?” he teases.

His eyes travel all the way down, then all the way back up Cas’s form.

“Multi-point inspection?” 

The angel shakes his head, suppressing a laugh.

“I’m here to tell the handsome, resident mechanic that lunch is ready,” Cas replies.

“Oooh... _handsome,_ huh?”

Dean gets to his feet and Cas swats at him playfully.

“Okay, okay. I’ll go get cleaned up and meet you in the kitchen,” Dean says.

  
He tidies up his work space a little bit and follows Cas inside. While Cas heads for the kitchen, Dean goes to the bathroom to wash up. He scrubs the dirt and grease off his hands, then walks to his and Cas’s room so he can change into some fresh clothes. He bends down to take off his work boots and suddenly the pain in his back returns. _He must have slept funny or something._ He goes over to the nightstand on his side of the bed and opens the top drawer, pulling out a small bottle of aspirin. He shakes two of the little white tabs into his palm and swallows them dry. _That should take care of that._ Dean then puts the bottle away and finishes changing before making his way to the kitchen. He’s pretty hungry, and he can’t wait to see what Sam and Cas made for lunch…

**Notes for the Chapter:**

> Thank you so much for reading, I hope you liked it!
> 
> I should have the next chapter up in a day or so! Until then! :)


	2. Crow's Feet

**Notes for the Chapter:**

> Hope you enjoy!

The second thing Dean notices, he discovers completely by accident. As he looks at his reflection in the bathroom mirror, he spots clusters of small lines at the corners of his eyes. They’re barely there, and honestly, he probably wouldn’t have noticed them if he hadn’t gotten an eyelash in his eye first thing that morning. He looks at them a little more closely. _Crow’s feet, he knows they’re called._ They aren’t very deep, but he can still see them clearly. Dean frowns. At first, he isn’t really sure what to make of them. He pokes at the skin near his eyes hesitantly, unsure if touching the tiny wrinkles will somehow make them worse. Then, he slides the tip of his finger over them. They don’t seem to look any worse than they did a moment ago, but they don’t look any better, either. Dean doesn’t know why _today_ he cares, when _yesterday_ he didn’t even realize he had them. Truth is, he's probably had them for a while, he just hasn’t noticed them until now. _How long?_ Dean thinks, all of a sudden. _How long has he had them?_

Dean is pulled out of his thoughts as Cas slips into the bathroom behind him, hair still tousled from sleep. The angel doesn’t strictly need sleep, but since coming to live with Sam and Dean— _for good and ever,_ Dean prays to whoever is listening—Cas has started indulging in human behavior much more frequently. He eats food on occasion, especially if Dean does the cooking. He drinks coffee in the mornings, and even has a few television series he likes to follow. Cas also takes naps when the mood strikes him, and he cuddles up with Dean each night, even if he doesn’t really _need_ to. Cas doesn’t need to shower either, but that doesn’t stop him from steaming up the bathroom every morning. The angel likes showers, despite the fact that he never really seems to get dirty. They’ve just become a part of his morning routine, along with kissing Dean when he first wakes up, or putting cream in his coffee at breakfast.

“Morning,” Dean says, glancing at Cas in the mirror.

Cas is wearing a fluffy bathrobe and a pair of striped pajama pants. _No shirt though._ Since they’ve convinced Cas that it isn’t necessary to wear three to four layers when they’re at home, the angel has endeavored to make himself as comfortable as possible. This means he frequently wanders around the bunker in one of Dean’s old t-shirts and sweatpants without any shoes on. He also sleeps in either a pair of boxers or some thin pajama pants, and basically nothing else. _Not that Dean minds in the slightest._ The angel shuffles over, wrapping his arms around Dean’s waist from behind, resting his chin on Dean’s shoulder. He mumbles something along the lines of “good morning” into Dean’s shirt and squeezes him a little tighter. A small smile plays at the hunter’s lips as he reaches a hand back to ruffle Cas’s hair, making it look even more wild than it already does. The angel presses a quick peck to the back of Dean’s neck and looks at him in the mirror.

“What are you doing?” he asks, his voice still deep from sleep.

Dean offers him a half-shrug.

“Just getting ready. Still need to brush my teeth.”

Cas hums before pressing another kiss to Dean’s neck, this one lasting a little longer. Dean smiles, resting his hands on top of Cas’s as the angel continues to hug him. 

“Need a shower?” Cas inquires.

“Nah, took one last night,” Dean replies. “You go ahead.”

The angel lets out a soft chuckle, like he finds something particularly amusing, and Dean can feel the sound vibrate through Cas’s chest. Cas plants a series of kisses along Dean’s shoulder. He presses into Dean’s back a little more firmly, looking intently at Dean through their reflection in the bathroom mirror. 

_“That isn’t what I mean,”_ Cas rumbles.

  
To emphasize his point, Cas slowly slides a hand under the fabric of Dean’s t-shirt, his fingers warm against Dean’s stomach. He leans forward and kisses the side of Dean’s neck once more, his lips lingering on the skin there. Oh. _Oh...Dean understands now._ He twists around in Cas’s arms so he can kiss him properly, letting the angel box him in against the bathroom counter. After a moment, Cas steps back from Dean to untie his bathrobe and shrug it off, letting it drop to the floor. He crosses over to the shower and turns on the water, letting it warm up. Cas then returns, his hands slipping beneath Dean’s shirt again, and Dean forgets all about the crow’s feet. _For a while, at least..._

**Notes for the Chapter:**

> Thanks again for reading, I hope you liked this chapter. I know it was a little short, but I promise the next one will be a bit longer.
> 
> Until next time! :)


	3. A Touch of Grey

**Notes for the Chapter:**

> As always, I hope you enjoy the latest chapter!

The third thing that catches Dean’s attention happens in the last place he would have expected. He notices it one morning at the barber shop, when he looks down at the bits of hair that have just been trimmed from his head. _Is it him, or do some of the pieces look just a little lighter than normal? A little more...grey-ish?_ Dean quickly pushes it aside, telling himself it’s probably nothing, just a trick of the light. And really, that isn’t too hard to do when he looks _this_ good—clean, sharp, and sure to get some attention from the angel waiting for him back at the bunker. He runs a hand along his jaw absentmindedly as he drives back home. _Bless barber shops and their complementary shaves._ When he gets to the bunker, Dean decides to spruce things up a little bit. And why not? He’s had one recent “upgrade” to his appearance, so why stop there? 

Dean sneaks through the bunker, making sure he doesn’t run into Cas. _He wants to surprise him, after all._ He slips into their room, closing the door gently behind him. He quickly strips off his flannel, followed by his t-shirt. Dusting himself off, just to make sure he doesn’t have any hair stuck to his skin from the barbershop, Dean walks over to his dresser and pulls out a nice cologne. It’s the one Cas got him for Christmas— _and boy, does it smell good on him._ Cas _loves_ the scent. Dean doesn’t wear it very often, but when he does, Cas is guaranteed to be in his personal space _all day._ He usually saves it for special occasions, but _what the hell, he’ll splurge today._ He squirts a little onto his neck and the top of his chest. _Oh yeah. He’s gonna be an angel magnet._ Dean then picks out a nice sweater, one that hugs his arms and torso _just right._ He pauses to check his appearance in the mirror. _There’s no way Cas is gonna turn down all this..._ He makes his way to the kitchen in search of the angel.

“Well, hey there, handsome,” a voice greets cheerfully.

Dean turns, then frowns. _It’s Sam. Of course Sam is teasing him._ Dean sighs and shakes his head, going over to the counter to make himself a cup of coffee. Sam leans back in his chair.

“Nice haircut,” he adds as Dean sits at the table. 

Dean gives him a look of fake surprise.

“Wow Sammy, I’m _shocked_ you still know what a haircut is, judging by the state of that... _whatever it is_ you’ve got going on,” he says, gesturing vaguely at Sam’s head.

It’s Sam’s turn to frown, and Dean chuckles lightly to himself, taking a sip of his coffee. A few moments later, Cas enters the room. It’s subtle, but Dean knows his efforts have already paid off. One of Cas’s eyebrows raises ever so slightly, the corners of his lips quirking up into a small smile. He doesn’t bother to announce his presence, he merely walks over to the table, sidling up to Dean. Cas’s arms wrap loosely around his neck and shoulders as he drapes himself over Dean. He presses a kiss to Dean’s temple, then rests his chin on Dean’s shoulder. Cas nuzzles under his ear and Dean can tell he’s picked up on the cologne. 

_“Mmmm,"_ Cas half-hums, half-purrs quietly in his ear. 

Dean grins widely at that, ridiculously pleased with himself. Sam clears his throat, gently reminding Dean and Cas that he’s still there. The angel stands up a little straighter so he’s not laying himself on Dean’s shoulders, and Dean endeavors to keep his expression as neutral as possible. 

“I, uh. I got a haircut,” Dean says, turning his head to look at Cas.

“I noticed,” Cas replies, running a hand through Dean’s hair.

“Do you like it? It’s a bit shorter on top than I normally get, but it’ll grow out.”

“It looks great,” Cas assures him. _“Very_ dashing.”

“Yeah, it really brings out the idiot in him this way too,” Sam adds, grinning.

Dean shoots his brother a look from across the table.

_“Bitch,”_ he grumbles.

“Old man,” Sam retorts.

Dean freezes. _It’s a jab._ But frankly, it’s not the jab Dean was expecting, even if it was a jab he deserved. Sam may have started things by teasing him, but Dean fired the first shot by making fun of his brother’s hair. It was only natural that Sam would fire back. _It shouldn’t bother him._ He and Sam say crap like that to each other all the time. _Picking on each other is part of how they, you know, express brotherly affection and whatnot. Always has been._ Dean can’t see _why_ the quip would upset him, especially when Sam is chuckling good-naturedly at him like he always does when they start taunting each other. _But it does. What if Sam really thinks he’s old?_ _And Cas? What about him? Does he think Dean’s getting old?_

If Cas cares about Sam’s comment—or even _hears_ it—it doesn’t show. The angel simply slides a hand under Dean’s chin, tilting his head up so Cas can kiss him. He places a soft peck on Dean’s lips, then goes in for something a little more steamy. Cas hums appreciatively as Dean begins to kiss him back, and Sam takes this as his cue to leave. Dean registers the fact that his brother is clearing out of the room, and he relaxes a little bit. _That’s right Sammy,_ he thinks. _Run for the hills._ If it wasn’t for the fact that Cas was now kissing along his jaw and the side of his neck, he would _totally_ go show his little brother how much of an _‘old man’_ he is. _He was the one who taught Sam how to fight, after all. And he could still kick Sam’s ass with one hand tied behind his back._

Cas hums again, pawing lightly at the front of Dean’s shirt. Dean tilts his head back a little more and sighs. _Damn, if this cologne isn’t just the best thing ever._ Suddenly, Dean gets to his feet, putting his hands on Cas’s hips. Cas flushes at the way Dean crowds into his space, and the sight makes Dean feel all jittery inside. He quickly uses his hands on Cas’s hips to turn the angel around, and begins walking them out of the kitchen. They make it to their bedroom, and not long after, the shirt Dean selected with intention ends up _who cares where_ on the floor. _All that matters is the gorgeous sight and the gorgeous sounds of the angel who’s suddenly obsessed with every inch of him…_

  
  


***

  
  


A while later, Dean flops onto his back, stretching out as Cas settles against his side. Cas has a lazy smile on his face as he traces little, invisible patterns on Dean’s chest with his fingertips, his eyes closed blissfully. _Old man, his ass. He’s still got it…_

**Notes for the Chapter:**

> Thank you for reading, I hope you liked it!
> 
> As usual, the next chapter will be up in a day or two! Until then! :)


	4. An Age Gap

**Notes for the Chapter:**

> When I first started writing this, I didn't realize how bittersweet some of the moments in this work are. This...this is one of those moments. 
> 
> That being said, I still hope you enjoy!

Dean shouldn’t be so surprised when it happens. But really, _surprise_ isn’t quite the right word for it. _Irritation_ is a much better word. _Indignance_ is definitely on the right track. _Territorial_ however, is perhaps the best description. When Dean walks out of the bathroom at the small diner where he, Sam, and Cas are currently having lunch, and sees two young women crowded just a _little too close_ to his and Cas’s side of the table, Dean instantly feels _very_ territorial. He knows, deep down, that he shouldn’t throw himself at Cas and do something that would get all three of them kicked out of the diner—and Dean doesn’t. But _good God,_ does he want to. Instead, Dean steels himself and walks back to their table. _Maybe they’re talking to Sam,_ he tells himself. _That’s it. They’re talking to his brother, not his angel._ Dean’s hopeful illusion is shattered the moment he gets within earshot of the two women.

“So...what do you do? Do you work at an office? I see you’re wearing a suit,” the shorter, blonde woman says.

Dean feels his blood begin to boil. _That’s his angel in a suit. Not theirs. And frankly, it just goes to show that they’ve been looking at him long enough to realize he’s wearing a suit. Most people just point out the trench coat._ Dean forces a smile when he gets close enough to their table.

“Excuse me, ladies,” he says, squeezing in beside them and taking his seat next to Cas.

They both look at him, not sure what to make of Dean. To clear up their confusion, Dean slides an arm around Cas’s shoulders and presses a quick press to his temple. Blessedly, Cas seems to enjoy the gesture. At first, the angel was a little uncomfortable with any public displays of affection, especially when he learned that some humans don’t take kindly to displays of affection between members of the same sex. But slowly, he warmed up to the idea. He and Dean spent so long dancing around each other that when they finally figured things out, neither one of them wanted to hold back if they didn’t have to. So now, when Dean kisses his temple in the middle of the diner, Cas smiles, leaning into him, and presses a responding kiss to the corner of Dean’s mouth. Dean couldn’t be happier about it. _Especially when it makes the two girls take a step back._

“I see you guys made some friends while I was gone,” Dean grins at his brother and Cas before glancing up at the girls. “And who might you two be?”

The blonde who was talking to Cas shifts her weight nervously. 

“I’m...Ashley,” she responds slowly. “Although...I think there’s been a bit of a misunderstanding...we’re, uh...we’re just gonna go.”

Dean does his best to look disappointed. 

“Oh. You...you sure you girls don’t wanna pull up a chair,” Dean offers, gesturing at the table. “I’m Dean, by the way.”

He knows they won’t take the offer. _Frankly, that’s the only reason he made it._

“Thank you, Dean,” the second one, a tall brunette, says. “But I think my friend and I are good. It was nice meeting you.”

With that, she turns and herds Ashely out of the diner. Once they’re finally gone, Dean relaxes a little. He keeps his arm draped along the booth behind Cas, though he removes it when the waitress brings out their food a couple minutes later. 

“Well, that could have gone worse,” Sam says, finally breaking the silence that had been hanging over them.

“Indeed,” Cas agrees. “At least they were nice about it.”

Dean takes a bite of his hamburger.

“Those girls looked like they were in college or something,” he remarks. “I ain’t one to judge, Sammy, but how exactly are you still reeling _their type_ in?”

Sam scoffs. 

“First of all...I am _not_ interested in that kind of an age gap,” he tells Dean.

Dean makes a noncommittal grunt.

“And secondly,” Sam continues, between bites of his salad. “They weren’t here for _me_ , now were they?”

Dean’s hamburger suddenly seems less appetizing. He sets it down, his shoulders drooping. Cas, who was picking at a side order of french fries during the previous exchange, pauses to look up at him. 

“Dean?” he asks, his tone concerned. 

Dean turns to look at him head-on, and that’s when he sees it. His behavior might be different, the way he sleeps at night, and wears pajamas, and nibbles at food, and watches television in the evenings. Even his expressions might be different, more open, more pure and unfiltered. Cas laughs more often and smiles whenever he’s happy. He gets angry from time to time, and isn’t afraid to scowl or furrow his brow. On rare occasions, Dean has seen Cas tear up when the angel gets sad or overwhelmed. So much about the angel sitting next to him has changed, and yet... _he’s exactly the same._ Every hair on his head, every feature on his face. He’s still Cas. He’s _literally_ the _same_ Cas that Dean met more than a decade ago. _What does Dean even look like sitting next to him?_

“Dean, are you okay?” Cas asks, pulling him out of his thoughts. 

Dean blinks at him.

“Yeah,” he says, smiling at Cas. “Yeah, I’m fine.”

  
He reaches over and gently strokes Cas’s cheek with his thumb. The angel leans into Dean’s hand slightly, then turns his head to press a kiss to Dean’s wrist. Dean lets his touch linger. _Cas loves him. Cas loves him, and he loves Cas. That’s all that matters...right?_

**Notes for the Chapter:**

> Thank you for reading! :)
> 
> As per usual, I should have the next chapter up in a day or so!


	5. My Favorite Soul

**Notes for the Chapter:**

> This chapter is a little longer than some of the others, but I think it all works out.
> 
> Enjoy!

“Dean? Is everything alright?” Cas asks, turning to look at him. 

The angel is sitting in bed, his back leaned against the headboard. He’s translating a passage from an old book into Enochian for Sam, and Dean has just given up on trying to read... _something._ He knows it’s a book, but in the last fifteen minutes or so, he hasn’t gotten through more than a page or two. The book is now sitting on his nightstand, and Dean is laying down on his side next to Cas. Listening to Cas translate has practically put him to sleep. The angel doesn’t recite _everything_ word for word, but the way he mutters constantly to himself in a low voice as he works is both adorable, and utterly soothing. Enochian itself isn’t exactly a very _pretty_ language. It’s not like listening to French or Italian. If anything, it’s more like listening to slowed-down German. _Kinda._ But for some reason, the way Cas forms the words, starting low in the back of his throat and letting the sound drift forward as each syllable washes over his tongue is one of the best things Dean has ever heard. _It’s also oddly relaxing._

“Hmm?” he hums, sleepily. 

Dean scoots closer and buries his face against Cas’s hip. Cas sighs, giving him a look that is equal parts smitten and exasperated. 

“I asked if everything is alright.”

“Yeah, yeah...you keep working, Feathers,” Dean yawns. “And feel free to keep translating out loud...love your voice.”

Cas smiles softly at that, reaching a hand down to stroke Dean’s hair.

“That’s not what I meant...I meant, are _you_ alright?”

Dean turns his head slightly and cracks an eye open at him. 

“Why wouldn’t I be?”

Cas sighs and closes the book, placing it, a notepad, and the pen he’d been using on his nightstand. Dean can sense a serious conversation brewing as Cas moves his pillow and lays down so that they’re facing each other. 

“You’ve been acting a little... _different_ since this afternoon,” the angel says quietly.

Dean immediately knows what Cas is talking about, a fact he doesn’t bother to hide. _The incident at the diner earlier that afternoon shouldn’t have bothered him so much...but it did._ Dean realizes he’s too sleepy to make excuses, and frankly, Cas would see right through them even if he wasn’t. He takes a deep breath, then exhales slowly.

“It’s...it’s gonna sound _stupid,”_ Dean begins.

Cas shakes his head, as if to assure him otherwise. Dean sighs.

“It’s those two girls from lunch.”

The angel furrows his brow. 

“What about them?”

Dean frowns.

“They were _young_ ,” he says.

“Yes, they were. Even by human standards,” Cas agrees. “And...that bothers you?”

“Not _that_ specifically.”

Dean tries to think of a way to explain what he means.

“Look, Cas. I’m not...I’m not exactly a young man anymore. I mean, I’m in my forties now, and I would have been _way_ too old for those girls.”

“Okay,” Cas says slowly, trying to understand where Dean is going with this.

“And they looked, you know, _your age,”_ Dean continues. “Or at least, the age you physically _appear_ to be.”

Cas follows Dean’s logic to the next step.

“So you think...that _you’re_ too old...for _me?”_ he inquires.

Dean nods. Cas does his best to hold back a smile, but must fail because Dean huffs and rolls over onto his back.

_“I told you it was gonna sound stupid,”_ he grumbles.

Cas places a hand on Dean’s shoulder. 

“Dean, I...I’m sorry,” Cas says softly. “But...I’m sure you see the irony in this.”

Dean makes a face, and Cas starts rubbing little circles on his chest to soothe him. 

“I don’t know _precisely_ how old I am in human terms, but I’m old enough to remember what your solar system looked like _before_ it was, in fact, a solar system.”

“Wait... _really?”_ Dean asks, looking at Cas with wide eyes.

The angel nods. Dean flushes. _Talk about an age gap..._

“Dean...what’s _really_ going on here?” Cas asks.

Dean finds himself unable to meet Cas’s gaze.

“I’m just worried about getting old, Cas,” he admits quietly. 

“Why?”

_“Because_...because my body won’t work the same, or look the same—it already doesn’t. I have little wrinkles and I’m starting to get grey hair, and my joints ache sometimes and...and one day you’re gonna wake up next to some old man who doesn’t even _look_ like me anymore. Is that _really_ what you want?”

There’s a beat of silence. Then, Cas props himself up on one elbow so he can look at Dean properly.

“Dean,” Cas says softly.

Dean frowns to himself.

“Dean, look at me.”

Slowly, Dean does. Cas moves his hand up to cup Dean’s face, his thumb stroking Dean’s cheek.

“I don’t care about those things. I don’t care about what you look like, or how old you are.”

“How can you say that, Cas?” Dean asks. “I mean...you drape yourself around me all the time. Are you _really_ telling me you’re still going to want to do that, and curl up in bed, and—and make out with me when I’m…”

Dean gestures uselessly. Cas’s gaze becomes unexpectedly hard. 

_“Dean Winchester,”_ the angel says firmly. “Those actions are a way of expressing my love for you...If you think even for a _moment_ that my love is based on your current physical appearance...you are _sorely_ mistaken.”

Dean stares up at him.

“Cas—”

“If you think that the only reason I’m affectionate with you is because of how you _look…”_ Cas shakes his head.

When Dean doesn’t say anything, Cas quickly climbs on top of him, sitting on his hips so that Dean looks up at him. He runs a hand through Dean’s hair.

“If you think I love his hair because of its color, you’re _wrong.”_

Cas’s hands come up to grab his face.

“If you think I love these eyes because of some number of years they’ve seen, you’re _wrong.”_

Almost angrily, Cas’s hands slide down, splaying on top of Dean’s chest.

“If you think I love this body because of how young it is, or what it looks like, you’re _wrong.”_

“Cas…”

The angel leans in, staring at Dean intently.

_“I love this body because it’s the one my favorite soul is attached to.”_

Before Dean can even _think_ of a response to that, Cas seals their lips together in a kiss. Dean wraps his arms around him, holding him close. Suddenly, Dean feels something warm and wet against his cheeks. In a moment of confusion, he thinks that perhaps _he’s_ the one crying, but when Cas breaks away, Dean can clearly see tears trailing down Cas’s cheeks. A pang of guilt rips through his chest as Dean reaches up and wipes them away.

“I’m sorry, I’m _so_ sorry,” he murmurs, pulling Cas into a tight hug. 

The angel lets Dean hold him against his chest, burying his face against the side of Dean’s neck.

_“I love you so much, Dean,”_ Cas manages. “There’s nothing I wouldn’t do for you... _Nothing.”_

Dean hushes him softly.

“Cas...it’s okay...It’s okay, I’ve got you.”

Cas lets out a shaky breath as Dean rubs mindless patterns in his back.

“I didn’t mean it like that, Cas,” Dean says after a moment. “But I...I understand now, okay? I’m so sorry, Cas, I never meant to hurt you.”

He kisses the top of Cas’s head, still rubbing his back. Slowly, the angel begins to relax.

“I love you, Cas...more than _anything,”_ Dean tells him. “You know that, right?”

Cas nods, hugging Dean a little tighter. 

“Good, because that’s _never_ gonna change...you got that, Feathers?”

The nickname makes Cas's lips twitch into a small smile.

_“I love you too, Dean.”_

  
Cas sighs deeply, and there’s an air of finality in the room. Dean rolls them onto their sides so they can get a little more comfortable and a few moments later, Cas drags himself away from Dean just long enough to turn off his lamp. Dean quickly settles in behind him, curling himself around Cas and pulling the covers up over them as if to shield Cas from the outside world. As Cas drifts off into sleep that night, he thinks about everything Dean said. He knows it’s his grace that’s kept his vessel from aging. _But maybe...maybe there’s something Cas can do to get around that..._

**Notes for the Chapter:**

> As always, thank you for reading, I really hope you enjoyed it! 
> 
> If you did, stick around for the remaining parts, there's only a few chapters left!


	6. 'I Love You'

**Notes for the Chapter:**

> As always, I hope you enjoy! :)

The next morning, Dean wakes to the feeling of Cas’s breath against his chest. At some point, Cas slid down off his pillow and buried his face under Dean’s chin while they slept. Dean pulls back to look at the snoozing angel, and in the gentle glow of the nightlight in the corner, he can make out some of Cas’s features. _Yes, they have a nightlight._ The bunker isn’t exactly known for its natural lighting, meaning they rely completely on electric lighting to see. At nighttime, the bunker is _pitch dark._ More than once, Dean has forgotten to turn a light on at night, and tripped while trying to find his way to the bathroom, subsequently startling Cas awake. To avoid broken bones or accidental angel blade stabbings, they agreed to put in a small nightlight. Dean gently pushes a lock of Cas’s hair back from his forehead, and kisses his temple. Smiling, he peppers Cas’s cheeks with kisses, and when Cas’s lips mumble something, he plants a kiss there too. Dean loves kissing Cas awake, and if the sleepy hums he makes are any indication, Cas loves it too.

_“Good morning,”_ Dean murmurs. 

_“Morning,”_ Cas yawns. 

“Ready to get up?”

Cas seems to contemplate this.

“Mmmm... _no.”_

It wasn’t easy to get Cas to start sleeping. But now that he’s developed a taste for it, it’s become quite the challenge to get Cas out of bed in the mornings. 

“Alright,” Dean says. “I’ll just let you sleep, then.”

He moves to get out from under the covers, when one of Cas’s arms wraps around him.

_“No,”_ the angel protests. _“Stay.”_

Dean sighs and goes to remove Cas’s arm when he feels a leg start to slide around him as well. 

“Come on, Cas. I need to get up.”

“No,” Cas reiterates, as if this settles things.

He then wraps himself fully around Dean, using both of his arms and legs to hold him in place. Dean struggles half-heartedly and lets out an amused laugh. He can feel Cas chuckle against his chest. Dean had been afraid that their conversation last night would put a damper on things, but it doesn’t appear that it has. 

“Cas, let go,” Dean complains.

Cas goes still for a moment, then suddenly twists to the side, pulling Dean on top of him. Dean lets out a surprised noise, quickly attempting to brace himself and failing. The movement jars his back, which is already a little stiff from sleep, but he hardly notices—Dean’s too busy trying to wrestle Cas’s hands off of him. Just when he pries one of Cas’s hands free, the angel manages to get a grip on Dean with his other hand. After this happens a couple of times, Dean lets out a groan of mock frustration and Cas starts to laugh a little more loudly. Eventually, Dean manages to get a hold of both of Cas’s wrists, pinning them down. 

“Dammit, Cas,” he grins, his voice cracking with laughter of his own. “I have things I need to do.”

“Oh, of course,” Cas teases. “ _Very_ important things.”

Dean sighs, still smiling. _He’s so glad that nothing’s changed._

“If I let you go, will you let me get up?” he asks Cas.

The angel is silent for a moment.

“Alright,” he mutters. 

Slowly, Dean releases his grip on Cas’s wrists and starts peeling himself away from him. Without warning, Cas suddenly wraps his legs around Dean even tighter and reaches up to pull him down into a kiss. Dean doesn’t resist this time, kissing Cas back as the angel snakes his arms around Dean’s neck. When they break apart, Cas laughs quietly against his lips. Dean shakes his head.

“What’s gotten _into_ you this morning? Hmm?”

He knows Cas is staring up at him, but in the dim light, Dean can’t _quite_ see his face.

_“Nothing...yet,”_ Cas replies, practically _purring._

Dean’s mouth falls open in shock.

“Cas!” he exclaims. 

The angel shrugs, feigning innocence. _Alright. If that’s how it’s gonna be…_

  
  


***

  
  


Dean sips his coffee blissfully. He glances to his left, meeting Cas’s gaze for a moment. The angel smiles at him, his eyes crinkling at the corners. Dean reaches over and pats the top of Cas’s thigh, then leaves his hand to rest there for a moment. Cas twines their fingers together, his thumb stroking at the back of Dean’s hand. After a while, Dean clears his throat.

“I think I’m gonna make something to eat,” he informs Cas quietly. “I’m getting kinda hungry.”

“Alright.”

Cas swats Dean’s behind as the hunter walks around the table to go make breakfast. Dean turns on his heel to face him, a look of surprise and amusement on his face. Cas chuckles at that, fine, little lines appearing at the edges of his eyes and mouth as he grins. _It’s so beautiful to see Cas this happy._ It makes Dean wish he would have thought to turn on a light in their room that morning, just so he could have seen the angel grinning up at him as he wrapped himself around Dean playfully. They’ve been together long enough that the ‘honeymoon phase’ should have worn off, but for some reason, each time it feels like they’ve finally settled into their relationship, something comes along and makes it all feel brand new again. _And Dean loves it. He loves Cas._ Sam picks that exact moment to walk into the kitchen, clearly sensing the atmosphere in the room.

“You two are in a good mood,” he points out quickly. 

Dean opens his mouth to speak when Sam cuts him off.

“It’s okay, you don’t need to tell me why,” he adds.

Dean frowns at his brother.

“I was just gonna ask if you wanted eggs for breakfast, you buzzkill.”

“Oh,” Sam mutters. “Uh, yeah, that would be great. Thanks, Dean.”

Dean looks over at Cas.

“You want any eggs, Sunshine?”

“No thank you, Dean.”

Cas smiles at him again, the little wrinkles at the corners of his eyes returning. _Little wrinkles. Hmmm._ Dean hasn’t noticed them before. _Maybe they’ve always been there, he just hasn’t paid attention._ On a morning like _this,_ it already feels like he’s seeing Cas for the first time. _Still...something seems different._ Dean’s pulled out of his thoughts however, when he sees Cas mouth the words, _‘I love you.’_ Dean grins like an idiot at that, ducking his head, and quickly forgets whatever he was thinking about. In fact, he even forgets he’s making eggs for breakfast until he accidentally drops one on the floor. Sam, who missed _none_ of their silent exchange, rolls his eyes.

“Here,” he says, walking over to Dean, “I’ll make the eggs. Go have a seat and try not to drop anything else.”

Dean does as he’s told and sits back down next to Cas. A moment later, the angel’s arms are wound around him tightly. Dean turns his head to whisper in Cas’s ear.

_“I love you too.”_

**Notes for the Chapter:**

> Thank you for reading, I really hope you liked this chapter! It was fun for me to write, so I'm hoping it was fun for you to read. 
> 
> Only a couple of chapters left, we're in the home stretch!


	7. The Baking Blunder

**Notes for the Chapter:**

> Enjoy! :)

Dean is in the library, reading when he hears the loud crash from the kitchen. Without hesitation, he leaps to his feet and runs towards the sound. He skitters into the kitchen, and frankly, _nothing_ could have prepared him for what he was about to see. 

“Cas?” he asks softly.

The angel has his back to him, his shoulders tense. 

“Cas, are you okay?”

Slowly, Cas turns around to face Dean, and Dean bursts into a fit of laughter. A fine layer of flour covers Cas’s entire upper body, all the way from his hair, down to his stomach. It looks like there might be cocoa powder in the mix as well, but Dean can’t tell. He has tears in his eyes from how hard he’s laughing. 

“Dean...it isn’t _funny,”_ Cas scolds weakly. “It...it—”

The angel sneezes suddenly and Dean starts to _cackle,_ leaning his weight against the doorway. As he slowly recovers, he can see the bowl Cas dropped onto the floor, identifying it as the source of the noise. A mess of flour, sugar, and cocoa powder litters the floor and counter. A wooden spoon teeters precariously on the edge of the counter, and Dean can see an open cookbook now covered in baking ingredients. When Dean fully calms himself, he notices that poor Cas is still standing there uselessly, arms held in front of him like he doesn’t know what to do. Dean sighs, feeling just a little bad for laughing at Cas.

“It’s okay, Feathers,” Dean says softly. “You go to the bathroom and get cleaned up. I’ll take care of this.”

Cas nods and shuffles out of the kitchen. Dean sets to work cleaning up the mess. He’s not sure how Cas managed to do it, but the angel got flour all the way on the opposite side of the kitchen, next to the table. Dean doesn’t question it though, he simply wipes down the counter, sweeps everything up, and goes over the trouble spots with a wet mop. Sam pokes his head into the kitchen when Dean’s nearly finished. The younger Winchester surveys the cleaning supplies, the open cookbook and the utter lack of anything in the oven. 

“I’m guessing there’s no brownies tonight?” he asks.

“Not unless they’re store-bought, Sammy,” Dean replies.

“Where’s Cas?”

“Bathroom.”

“That bad, huh?”

_“Oh yeah,”_ Dean chuckles.

Sam offers him a sympathetic shrug that says _‘whatcha gonna do?’_ and pops back out of the kitchen. Dean finishes cleaning up and heads to the bathroom to see how Cas is doing. When he slips inside, he finds the angel standing awkwardly in front of the sink, trying to clean himself off with a washcloth and failing. 

“Oh, it’s gonna take more than that, Cas,” Dean says.

Cas has cleaned enough of the flour off his face so that Dean can now clearly see the pitiful look Cas gives him. Dean sighs at him fondly, then crosses over to the shower. He turns on the water and motions for Cas to come closer. Carefully, he strips the angel out of his shirt, leaving it turned inside-out so that the flour on it doesn’t get all over the floor. He then instructs Cas to finish undressing while he checks the temperature of the water. A moment later, he’s herding Cas into the open shower and reaching for the shower head. It’s moments like these that Dean’s grateful he installed detachable shower heads in the bunker. This way, he can hose Cas down without getting himself soaking wet. _It also makes getting clean after a particularly gnarly hunt easier too, but moments like these are much more preferable to think about._

The angel runs his fingers through his hair and scrubs the botched brownie mix off of his face and arms as Dean maneuvers the shower head around him, making sure there isn’t any flour or cocoa powder they missed. It isn’t a proper shower, but it’ll do. Dean turns off the water and replaces the shower head, then fetches Cas a clean towel from the nearby cupboard. Cas quickly dries off and wraps the towel around his waist. Dean picks up the angel’s dirty clothes and takes them to the laundry room while Cas goes to their bedroom. Dean throws the flour-caked clothes into the wash, then slips inside their room, shutting the door behind him. The angel is still wearing nothing but a towel, sitting on the edge of their bed, pouting. Dean knows he’s upset about not being able to bake. Since discovering he has the free time to do virtually whatever he wants, Cas has tried taking up hobbies. _Like baking._ Unfortunately, Cas doesn’t seem to be having too much luck. And while Dean does his best to encourage him, he knows Cas is beginning to get very frustrated. 

“Hey, it’s okay,” Dean says, having a seat on the bed next to Cas.

“Easy for _you_ to say,” Cas mumbles. “You don’t destroy the kitchen every time you try to make something.”

“Well...that’s just because I’ve had more practice than you, Cas.”

Cas frowns.

“I still ruined something as easy as brownies...I didn’t even get all the ingredients together this time!”

He huffs and Dean wraps an arm around him. Perhaps he shouldn’t find the angel so adorable when he gets upset, but he does. There’s something amusing, and almost _pure_ in the way Cas gets so absorbed in doing something human like making brownies. Dean leans into him, smiling.

“Well, I think Sam and I can live without dessert tonight. And between you and me Cas...there are things I like a lot more than brownies.”

He leans over and pecks Cas’s cheek quickly.

“Like _you,”_ he says, trying to cheer the angel up.

Cas’s lips twitch slightly.

“And your _lips_...and your _nose_...and your _chin,”_ Dean murmurs, marking each phrase with a kiss to the places he lists off.

Cas laughs lightly, grabbing at Dean’s shoulders. 

“And your _hair...”_

Dean runs a hand through it and finds it still dripping wet. 

“That you _apparently_ didn’t dry that well when you got out of the shower,” Dean adds.

He grabs at the towel around Cas’s waist and tugs it off, quickly draping it over the top of Cas’s head. Dean starts to ruffle his hair with the towel, making it stick out in every direction. Cas chuckles at that, pulling Dean closer as the hunter briskly rubs his hair dry with the towel. Satisfied that Cas’s hair is now dry—and completely _wild_ —Dean lets the towel fall around Cas’s neck and shoulders, using it to pull the angel in close. Cas happily slings a knee over Dean’s legs so he can sit in his lap, winding his arms around Dean’s neck. Dean lets go of the towel, letting it slide down Cas’s back. He runs a hand through Cas’s hair once more, smiling up at him, and _that’s_ when he sees it. Right at the edges of Cas’s temples are tiny, little patches of greying hair. Dean's smile quickly fades to abject horror.

“Dean? What’s wrong? Are you okay?” Cas asks him gently, cupping his face.

_No, he’s not okay. But more importantly, Cas isn’t okay. He’s not supposed to have grey hair..._

**Notes for the Chapter:**

> As always, thank you for reading! 
> 
> There's only one chapter left! How will things end? What has Cas done? And what will Dean think about it? Stick around to find out!


	8. Aging (with Grace)

**Notes for the Chapter:**

> Final chapter! I hope you enjoy!

Cas, sensing that something is very wrong, quickly removes himself from Dean and pads over to their dresser. He throws on a shirt and a pair of boxers before returning to the bed. Dean hasn’t moved. He’s still sitting on the foot of the bed, staring at Cas like he expects the angel to disappear at any moment. Cas has a seat next to him, turning to face Dean head-on. The look Dean gives him nearly breaks Cas’s heart. His eyes are watery and his lips tremble as he hesitantly reaches out to touch Cas.

“Cas…” he whispers. “Please...please tell me that you didn’t…”

He bites his lip, fingers just brushing against the greying hair on Cas’s temple.

“Dean?” Cas asks quietly. “What’s wrong?”

“You...you have grey hair,” Dean says, his voice incredibly small. 

He looks at Cas’s face a little more closely.

“And little wrinkles.”

Cas nods his understanding. 

“Yes,” he says nodding. “I know. I thought that—”

Dean suddenly grabs the front of Cas’s shirt, an unexpected anger washing over his features.

“Cas, tell me you didn’t give up your grace,” he manages through gritted teeth. “Tell me you didn’t do something like that because of a _stupid_ thing I said!”

The anger fades as quickly as it appeared, and Dean hangs his head, still clinging to Cas. Cas pulls him in closer. He wraps his arms around Dean’s middle, drawing him in for a hug. After a moment, Dean’s arms wind around Cas’s neck. He buries his face in the top of Cas’s shoulder.

“Cas, _please_ tell me you didn’t—”

“I didn’t, Dean,” the angel says softly. 

He starts to rub Dean’s back. 

“I just wanted to make you more comfortable...I saw that the thought of you aging while I remained the same made you _uncomfortable_ and...and I wanted to fix that.”

Dean pulls back to look at him.

“But...but if you’re still an angel, then how did you…”

Cas smiles at him. He reaches a hand up and strokes Dean’s cheek. Dean leans into the touch. He still looks afraid, but he’s attentive, waiting for Cas to explain. Cas sighs softly.

“Think of it like...diverting power. I decided that preserving the physical nature of my vessel wasn’t important, so I... _rerouted_ that energy. Does that make sense?”

Dean stares at him for a moment.

“So you...you’re mortal now?” Dean asks.

Cas considers this.

“To a degree, yes,” he replies. “I still can’t get sick and mortal weapons still won’t be able to harm me.”

Dean digests this information. When he realizes that Cas is physically alright, he relaxes slightly.

“But...why would you do that?”

Cas furrows his brows.

“Obviously I did it for _you,_ Dean. I wanted you to be happy, and...I wanted you to have a normal life. I wanted you to have someone you could, you know... _grow old with.”_

Dean blinks at him.

“Isn’t that usually something people want?” Cas asks.

“It is, Cas, but...you’re really willing to do that?” Dean asks. “You’re okay with growing old?”

Cas shrugs.

“It’s only temporary Dean. My lifespan is... _quite considerable_ compared to the average human’s. A few decades or so is nothing for a being like me.”

The angel can tell based on the look Dean gives him that this wasn’t the right thing to say. He runs a hand through Dean’s hair, attempting to soothe him. 

“And _then_ what, Cas?” Dean says, his voice shaking. “You’re just gonna be stuck here after...after I _die_?”

Cas shakes his head.

“No, Dean. That’s exactly why I didn’t give up my grace. I don’t have a soul, so without it, I have no way into Heaven,” Cas tells him matter-of-factly.

Dean looks at him, struggling to understand. Cas presses a kiss to his cheek, still stroking his hair.

“If anyone has a place there, it’s _you,”_ the angel says. “When your time here on Earth is done, that’s where you’ll go. And _when_ you go there, I’ll follow you. I’ll stay here, like a human, with you for as long as you live. Then, when your time is up, I’ll meet you in Heaven.”

Dean stares at him, wide-eyed.

“So...you’re saying that you want to be with me... _forever?”_

Cas nods. Dean lets out a shuddering sigh.

“All I did was allow my vessel to catch up to its physical age here on Earth,” Cas continues. “I was hoping it would be more gradual, so I would have the time to come up with a way to tell you, but...obviously this is new for me.”

He laughs nervously and Dean manages a smile.

“I’m sorry, Dean. If you don’t like it, I can revert my vessel’s state, and—”

“No,” Dean says quickly. “I...I don’t care about that, Cas. I just care if you're okay.”

“I’m more than okay, Dean,” Cas says softly. “I’m _happy._ I’m happy to do this for you, and experience new things with you. I wouldn’t want anything else, I know that now.”

Dean leans their foreheads together. Cas pulls him in for a proper hug once more. After a long moment, their lips meet in a gentle kiss. Cas leans them back so they’re half laying on the bed. _It’s easier to hold each other this way._ Dean wraps his arms around him, pulling Cas onto his chest. The angel smiles down at him, resting a hand over his heart.

_“I love you, Dean Winchester,”_ he murmurs.

_“I love you too, Castiel.”_

They share another kiss. Dean reaches a hand up to cup Cas’s face, examining his features carefully.

“So...if you’re gonna age like a normal human...does this mean you’ll ever get reading glasses?” Dean asks suddenly.

Cas gives him a confused look.

“Why would I get reading glasses?”

Dean shrugs.

“Well, when people get older, their eyesight doesn’t always stay the same.”

He looks at Cas for a moment, biting his lip.

“Plus, I think it could be a good look on you,” Dean adds casually.

Cas hums, contemplating this.

“I’m just saying,” Dean continues. “The sexy librarian look is right up your alley, Cas.”

The angel rolls his eyes. _Leave it to Dean to turn their serious conversation in this direction._

“I’ll _consider_ it,” Cas says after a moment.

He gives Dean a curious look.

“But I have to warn you...there will be some very serious penalties for late books.”

Dean grins up at him.

“Oh yeah? Why don’t you tell me a little more about those.”

He pulls Cas in for another kiss.

“Just so I understand what I’m getting into,” Dean adds. “Terms and conditions, and all that.”

  
Cas chuckles softly and leans down to whisper in Dean’s ear. He tells him all about the _‘terms and conditions.’_ And about how much he loves him, and how much he needs him, and how he can’t wait to spend every day for the rest of eternity at Dean’s side, no matter what form they’re in...

**Notes for the Chapter:**

> Thank you so much for reading! It was interesting to write something a little bittersweet, as I haven't really done that before. 
> 
> Again, thank you for taking the time to check this story out, I hope you liked it! :)


End file.
